Add TransitivePackagingSpecs

Add TransitivePackagingSpecs to return the PackagingSpecs for a
module and any of its transitive dependencies that have dependency
tags for which IsInstallDepNeeded returns true.

Bug: 124313442
Test: m checkbuild
Change-Id: I1d6750db830d1601d696349674f0b7071372ca11

android/packaging.go

@@ -203,3 +203,23 @@ func (p *PackagingBase) CopyDepsToZip(ctx ModuleContext, zipOut OutputPath) (ent
 	builder.Build("zip_deps", fmt.Sprintf("Zipping deps for %s", ctx.ModuleName()))
 	return entries
 }
+
+// packagingSpecsDepSet is a thin type-safe wrapper around the generic depSet.  It always uses
+// topological order.
+type packagingSpecsDepSet struct {
+	depSet
+}
+
+// newPackagingSpecsDepSet returns an immutable packagingSpecsDepSet with the given direct and
+// transitive contents.
+func newPackagingSpecsDepSet(direct []PackagingSpec, transitive []*packagingSpecsDepSet) *packagingSpecsDepSet {
+	return &packagingSpecsDepSet{*newDepSet(TOPOLOGICAL, direct, transitive)}
+}
+
+// ToList returns the packagingSpecsDepSet flattened to a list in topological order.
+func (d *packagingSpecsDepSet) ToList() []PackagingSpec {
+	if d == nil {
+		return nil
+	}
+	return d.depSet.ToList().([]PackagingSpec)
+}